The present invention relates to an apparatus and related method for heating and melting solid lubricants (Hot-Melts) in the delivery drum, to allow their transfer by pumping into the containers for servicing oiling machines, specifically electrostatic ones.
Solid lubricants for laminates, known also as “Hot Melts”, “Dry-film”, “Dry-lube”, etc. are solid products at room temperature and their melting point is in the order of 30+50° C.
They are usually delivered in metal drums capable of being fully opened, into which they were poured by the manufacturer.
For their use in electrostatic oiling machines, they must be liquefied by heating beyond the melting point.
This can be obtained in various known manners, for instance using electric shell drum heaters, or introducing the drums themselves into heated chambers and leaving them therein until the content is fully melted.
It is then necessary to move the warm drums and transfer their content into the thermostatic service containers of the oiling machines.
However, this operation is not only impractical, it also requires very long times and a great expenditure of energy.
This is due to the fact the heat conductivity of the solid mass of the lubricant is very poor and therefore the energy applied to the exterior of the container (shell heaters, hot chambers) penetrates very slowly into the mass.
The product near the walls of the drum melts rather rapidly, but the temperature within the solid mass rises at an extremely slow rate, because of the poor heat conductivity of the product and of the absence of convective currents.
The present invention aims to reduce the time required for melting and facilitate transferring the product.